Included in this glossary are technical terms associated with the collection, processing, and tabulation of 1970 census data: terms used in the technical description of census summary files on magnetic tape; and other terminology which may be used in meeting requests for census data or special services. Also included are frequently used abbreviations, many for geographic areas are defined in the Census Users Dictionary.

ACG (Address Coding Guide)

A computer listing of streets by block sides, Each record identifies a single block side by a range of addresses, block numbers, tract numbers, and other geographic codes. This geographic tool, created for the city mail delivery areas of 145 SMSAs, does not contain confidential information and is available to the general public on a cost basis.

A listing of all addresses in mail-out/mail-back areas for housing units (occupied or vacant) and other living quarters. It was used in the preparation of questionnaire mailing labels, for drawing samples of dwelling units, etc. This file is confidential and cannot be made available to any other governmental agency or the public.

Assignments of acceptable entries in place of unacceptable or missing entries on a basic record. Such assignments are made where an entry on a given item is lacking or where the information reported for a person on that item is inconsistent with other information for the person.

Computer tapes containing the records of edited census information about each housing unit and each person. Neither names of household members nor addresses are included in these files. These data records are cross-referenced to the Address Register records by address serial number. The BRT and Address Register files are confidential and access to them is restricted to Census personnel for use in developing statistical summaries.

A numbering system based on 2 digits, O and 1. It permits representation of information on magnetic tape and in computers. A binary condition exists if there is or is not an electrical pulse or a magnetic force at a particular location in a computer memory or on a tape.

A special form prepared and inserted as the first page of each enumeration book to identify the ED during processing, to record preliminary counts of population and housing, and to separate one ED from another.

Tabulations are often referred to as being composed of tally cells. One cell contains a number representing the count (tabulation) of some kind of unit, such as a person, house, or business, possessing some kind of characteristic; e.g., a certain age or marital status, Refer to Data Access Description CT-1 (revised).

A unit of the Bureau of the Census which did extensive small area data research in New Haven, Connecticut after the 1967 special census there. The study explored the uses of census statistics at the local level and the integration of census information with data from other sources.

Collections of bits representing symbols which are intelligible when displayed on a printer or other computer output device,
May mean the symbol itself. Characters may represent alphabetic, numeric, and other symbols such as + or - signs.

An operation in the processing of census data in which handwritten entries on the questionnaires (occupation, place of work, etc. ) are assigned numeric codes by filling appropriate circles which can be then processed through FOSDIC. A coder assigns a code for each entry according to a detailed set of instructions and fills appropriate circles on the census questionnaire.

Data presentations which are constructed from existing tabulations. If a users needs may be met by reorganizing existing tabulations or calculating measures from existing tabulations, the work is termed a compilation.

Census data tallies for portions of States and SMSAs. For example, four types of SMSA component summaries follow each SMSA summary in file B of the Second Count summary tape. They include: (1) Each county inside SMSA; (2) each central city or city of 50,000 or more population inside SMSA; (3) urban balance of SMSA; and (4) rural balance of SMSA.

Techniques for graphically displaying data using a computer and associated output devices such as a printer, pen plotter, or cathode ray tube. Through the use of computer graphics, large amounts of data can be easily visualized or displayed.

The process of changing information from one physical form of representation to another, such as from the bit arrangements required by one type of computer to that required by another. At the Census Bureau, the term usually has reference to operations performed on tapes produced by the Bureau computers so that they will be compatible for use on other computers.

A research and development division of the Bureau of the Census primarily concerned with making census data more accessible and useful to users in government, private industry, and the academic community.

The number of characters or groups of bits recorded on an inch of tape. Frequently used densities are 556, 800, or 1600 cpi (characters per inch). A particular computer system is capable of reading only certain specified densities of magnetic tape. (See CPIand Recording density. )

The operations in the processing of census data which involve checking the data for completeness, consistency, and meaning. For example, household heads must be at least 14 years old, wives must be married, medical doctors must have college degrees, etc. Editing is usually done by the computer. (See Allocation. )

A reserved area in a record which serves a similar function in all records of that group of records; a specified area of a record used for a particular category of data. For example, the codes indicating which geographic area a tabulation represents may be located in a field at the beginning of that tabulation record.

Both a logical and physical record that contains descriptive information for a group of logical records which are to follow. Header records for census summary and basic record tapes generally contain codes identifying the geographic areas represented by the subsequent file. Volume label is one type of header label.

In reference to Census Bureau summary tapes, a set of data items for a particular geographic area accompanied by a set of geographic identifiers. A logical record maybe a part of a physical record or may consist of one or more physical records. A logical record may also refer to a set of data for any unit of analysis such as an individual, household, or housing unit as carried on census basic record tapes.

A term used in reference to the 1970 census sample questionnaire (the questions range in number from 66 to 74) which was distributed to 1 out of every 5 households or 20 percent of the population. There were two versions of the long form: the 15 percent long form sent to 15 out of every 100 households and the 5 percent long form sent to 5 out of every 100 households.

A collection technique used in the 1970 census by which persons, usually those living in large metropolitan areas, were asked to mail back their completed questionnaires rather than waiting for an enumerator to pick them up.

A procedure involving matching individual census records to a list of names and addresses and preparing statistical summaries of census characteristics from the records. The confidentiality of replies to census questions is preserved in the preparation of matching studies.

A set or block of characters on magnetic tape which is read into a computer as a unit; may be referred to as a block or a recording block. Physical records are separated by interlock spacing on the tape. Each physical record may contain one or more logical records or some fraction of a logical record requiring more than one physical record.

A sample of census basic records for individual persons and households, made available for statistical use outside the Census Bureau. Identifying information, such as name and detailed geographic location, are omitted to preserve the confidentiality of the census records.

A procedure for determining whether or not a general or special census product may be released to the public. Decisions are based on concern for confidentiality, adequacy of documentation, and statistical validity.

A special machine which reads a summary tape, operates on specific formatting instructions, and arranges the tapes contents for photographing. It is used in producing microfilm copy of the First and Third Count summary tapes.

The document or questionnaire on which answers to census or survey questions are recorded. The 1970 census used three kinds of schedules: the short form, which includes only the complete-count questions; and two versions of the long form which include both complete-count and sample questions.

Term used to designate jobs or special services undertaken for persons or institutions outside the Census Bureau on a reimbursable or cost basis. These jobs may involve the copying of summary tape files or the preparation of photocopies of tabulations, etc. (See Special tabulations .)

Retabulations of the census basic record tapes (BRTs) at users expense to obtain data summaries for geographic areas not recognized in general tabulations and/or including subject breakdowns or cross-classifications not appearing in general tabulations.

An operation of selecting and copying specified data for only a few geographic areas and/or tabulations from a data source; for example, copying selected data from a complete summary tape to a deck of cards.

A BCD code in which numbers are represented by the binary equivalent of that number plus three. XS-3 codes are used in Univac programs at the Bureau. Their alphabetic and symbolic parts are not equivalent to IBM BCD codes.

Abbreviations for Selected United States Government Agencies, Offices, and Other Units